highlight unread message row in light blue

This addresses issues with seeing unread notifications by highlighting them as light blue, along with more opaque icons

src/components/social-message/social-message.scss

@@ -12,6 +12,10 @@
     opacity: .25;
 }
 
+.social-message.mod-unread {
+    background-color: lighten($ui-blue, 40);
+}
+
 .social-message.mod-unread .social-message-icon {
     opacity: 1;
 }